As a copy editor, it is important to ensure that your writing is clear, concise, and grammatically correct. One of the key elements of good grammar is subject-verb agreement. Simply put, this means that the verb in a sentence must agree with its subject in both number and person. In other words, if the subject is singular, the verb must also be singular. If the subject is plural, the verb must be plural as well.

The formula for subject-verb agreement is fairly simple. In order to ensure that your writing is grammatically correct, you should follow these guidelines:

1. Identify the subject: The first step is to identify the subject of the sentence. The subject is the noun or pronoun that is performing the action in the sentence. For example, in the sentence „John is running,“ John is the subject.

2. Determine the number of the subject: Once you have identified the subject, you need to determine whether it is singular or plural. If the subject is singular, use a singular verb. If the subject is plural, use a plural verb. For example, in the sentence „The boys are playing,“ boys is plural, so the verb (are playing) is also plural.

3. Consider the person of the subject: The final step is to consider the person of the subject. This simply means whether the subject is first person (I, we), second person (you), or third person (he, she, it, they). The verb must agree with the person of the subject. For example, in the sentence „I am writing,“ the subject (I) is first person, so the verb (am writing) is also first person.

It is important to note that there are some exceptions to these rules. For example, some nouns that look plural may actually be singular (e.g. news, mathematics) and some nouns that look singular may be plural (e.g. pants, scissors). Additionally, there are irregular verbs that do not follow the typical subject-verb agreement rules (e.g. „I am“ instead of „I is“).

In conclusion, subject-verb agreement is a vital component of good grammar. By following the simple formula of identifying the subject, determining its number, and considering its person, you can ensure that your writing is clear, concise, and grammatically correct.